Bill, re reply 38:
there has been a lot of studies of the behaviour of sediments under marian conditions, including both mathematical models and wind tunnel studies. These have then been cross checked against the known properties of martian dunes.
As far as I recall the results that sediments are entrained at velocities an order of magnitude higher on mars than on earth because of the lower density. However, once entrained, the saltation height is much greater, because of the lower gravity. As a result Martian dunes are much higher in relation to their wavelength than terrestrial ones. To the best of my knowledge the sand-silt distinction hold true on Mars, as on earth.
Cheers
Jon
